Blasting methods are known from the state-of-the-art. Common to them is that a means for mechanical processing of surfaces (hereinafter also: actual blasting agent), which is usually a granular material, is shot onto a surface to be blasted. Here, granular material refers to a granular material in the broadest sense of the term, i.e., a material consisting of particles with a defined size distribution, and where symmetrically shaped particles such as spheres shall also be considered granular material below. The shape, the size distribution and the material of which the granules are made are selected according to the material of the workpiece to be processed and the desired effect of the blasting procedure on the workpiece. The purpose of the procedure may be to free a surface of an old coating, to prepare a surface for a new coating, but also to polish the surface or improve its mechanical properties.
Accordingly, edged granular material is often selected as blasting agent, for example, if the processing purpose is to remove material from the surface or to roughen a surface, or round granular material is selected if the surface is to be polished or its mechanical properties are to be improved, for example, using the so-called shot blasting. In principle, however, material can also be removed using round granular material.
A variety of materials can be used as blasting agents, for example steel, cast iron, corundum, glass, garnet sand, and—depending on the purpose—even more exotic materials such as crushed nutshells. The grain typically varies from 0.1 to 3 mm.
Parts that have grease, oils, silicone oil layers, release agent residue or similar substances on their surfaces to be blasted are problematic for conventional blasting methods. Because the blasting agent typically runs through a circular process and is re-used in blasting systems, such types of workpieces lead to an enrichment of contaminants in the blasting agent, causing increased need for cleaning of the blasting system and the blasting agent. For this reason, prior cleaning of the workpieces is often prescribed by blasting system manufacturers, which causes significant health and environmental risks and thus additional costs due to the solvents used.